Back digging shovel



May 2, 1933. M. L. FYKSE BACK DIGGING SHOVEL Filed Dec. 16, 1929 2 Sheets-Sheet 1 Wag gm A TTORN E YS.

y 2, 1933- M. L. FYKSE 1,906,746

BACK DIGGING SHOVEL Filed Dec. 16, 1929 2 Sheets-Sheet 2 .fiz'fcell Lizzy 375e, IN VEN TOR.

BY 1 1, W

A TTORNEYS.

- UNITED STATES PATENT OFFICE...

' Patented May. 2, 1 933 MITCHELL L. rYxsE, orsourn MILWAUKEE, WISCONSIN, ASSIGNOR r menus. 1

ERIE COMPANY, or soo'm MILWAUKEE, isconsin; A conrona'non or pm WARE ' BACK; DIGGINGISHOVEL Application filed December 16, 1929. Serial No.-414,884.'

My invention relates to new and useful improvements in back digging shovels.

Back digging shovels are well known in the excavating art. They are characterized by a dipper mounted on the lower end of a-handle, which is pivoted intermediate its ends on the outer end of the boom, the inner end of the boom being pivoted to the frame of the machine. The shovel faces toward the machine. On the main frame of the machine is a two-drum winch, from which one rope, associated with the dipper, tends to drag the dipper toward the machine. The other rope of the winch is associated with the upper end of the dipper handle and tends both to raise the boom and to cause the dipper to move away from the machine. 3

The principal object of my invention is to provide novel tripping means for the pivoted dump door of such a shovel, and more particularly to provide means whereby a mini.- mum of slack shall occurin the trip rope during the digging operations.

Another object of my invention is to pro vide means whereby the shovel can dig a.

trench materially wider than the digging dipper, while progressing in a single straight line along what is tobe the center line of the trench.

Further objects and advantages of my invention will be readily evident, as the de scription progresses.

The invention consists in the novel parts, and in the combinations and arrangements thereof, which are defined in the appended claims; and of which one embodiment is exemplified in the accompanying drawings, which are hereinafter particularly described and explained. i 3

Throughout the description, the same reference number is applied to the samemember or to'similar members. i

Figure -1 is a side elevation of a power shovel embodying my invention; T

Figure 2 is an enlarged View of thepivot between handle and boom of my shovel, viewed in the direction of the arrows 2-2 of Figure 1. I

Figure 3 is an enlargedview of the open endof the digging dipper, viewed in the direction-of the arrows 33 of Figure 5.

' Figure 4 is a section of-the digging dipper,

viewed in the direction of the arrows 4'4:

of Figure'3.

Figure 5 is an undetailed plan'view of a power shovel embodying my invention, engagedin digging a ditch of considerable more width than that of the digging dipper.

Referring to the drawlngs, it will beseen that 11 is the mainibase of the power shovel,

supporting .a boom 12, an A-frame 13, and a main winch 14.

The main winch 14 includes two drums 15 and =16, actuab'le by any convenient power source (not shown).

Turning now to Figure 2, we see that a lug The boom 12 is pivoted to. the base 11 at On the lower end of the handle 21 is secured adigging dipper 28 with front teeth 7 29 and side teeth30. The front, or bottom, 31 is pivoted to the rest of the dipper at 32, and is held in closed position by a latch 33. From this latch runs a rope 34 over sheave 24,

through the axis 23 of the hinge pin 22, and

over sheave '26 to an anchorage35 on the A-frame 13. I

.There is a sheave 36 on the upper end of the handle 21, and a sheave 37 on its lower end- The digging operations are performed, in a manner well known to the art, by means of ropes 38 and 39 in cooperation with sheaves 36 and 37, and winch drums'15 and 16. 3

Turning now toFigure 4, it will be seen that the sides 40 of the dipper 28 are flat, and.

are very materially flared outwardly vfrom the closed end of the dipper to the open end carrying the teeth. ,This. flare, combined with the side digging teeth 30, enables the dipper to dig a trench of considerablemorethan its own width, as is shownin Figure 5, without the shovel departing from a position on the prospective center line of the trench.

Reverting to Figure 2 it will also be seen that the reeving of the trip rope, therein detailed, renders it possible for the rope to con form to all digging movements, without the introduction of any considerable amount of slack therein. In an ordinary power digging shovel, by far the greater amount of slack in the trip. rope is due to the swinging of the handle "about the outer end of the boom, rather than to the raising and lowering of the boom. This principal cause of slack has been eliminated by my invention. l

I wish it to be understood that my invention is not to be limited to the specific form or arrangement of parts hereinbefore described, eXcept with respect to any claim which imposes such limitations.

I claim: i

1. In a back-digging shovel, the combination of: a main frame; a boom, pivoted at its lower end to the frame, for swinging in a vertical plane about its pivot; a dipper handle, pivotally attached, intermediate its ends, to the outer end of the boom, for swinging in a vertical plane about its pivot; means tending to hoist the boom and swing the handle away from the frame; means for swinging the handle toward the frame; a digging dipper, on the lower end of the handle, and facing toward the frame; a dumping door for the dipper; latch means for the door; two sheaves, mounted adjacent the point of pivotal attachment of the handle to the boom; and a trip rope for the latch, constrained by the two sheaves to pass between the two sheaves substantially through the axis of the pivotal attachment of the handle to the boom, and thence to an anchorage on the frame.

2. In a back-digging shovel, the combina tion of: a main frame; a boom, pivoted at its lower end to the frame, for swinging in a vertical plane about its pivot; a dipper handle, pivotally attached, intermediate its ends, to the outer end of the boom, for swinging in a vertical plane about its pivot; means tending to hoist'the boom and swing the handle away from the frame; means for swinging the handle toward the frame; a diggingdipper, on the lower end of the handle, and facing toward the frame; a dumping door for the dipper; latch means for the door; a sheave on the handle adjacent the handle-boom pivot; a sheave on the boom adjacent the handle-boom pivot; and a trip rope for the latch, led over the sheave on the handle, through the handle-boom pivot, and over the sheave on the boom, and thence passing to an anchorage 011 the frame. 8. Ina baclecligging shovel, the combination of: a main frame; a boom, pivoted at its lower end to the frame, for swinging in a vertical plane about its pivot; a dipper handle, pivotally attached, intermediate its ends, to the outer end of the boom, for swinging in a vertical plane about its pivot; means tending to hoist the boom and swing the handle away from the frame; means for swinging the handle toward the frame; a digging dipper, on the lower end of the handle, and facing toward the frame; a dumping door for the dipper; latch means for the door; and a trip rope for the latch, passing through the axis of pivotal attachment of the handle to the boom, to an anchorage on the frame.

In testimony whereof I aflix my signature.

MITCHELL L. FYKSE. 

